N, n, n&#39;, n&#39;-tetrakis(p-nitro- or amino-substituted-phenyl)-p-arylenediamines



United States Patent 3,251,381 N,N,N',N'-TETRAKIS(p-NITRO- 0R AMINO-SUB- STITUTED-PHENYL)-p-ARYLENEDIAMINES Peter Vincent Susi, Middlesex, and Norma Ann Weston, Semen-ville, N.J., 'assignors to American Cyanamid Company, Stamford, Conn., a corporation of Maine No Drawing. Filed July 16, 1963, Ser. No. 295,524 5 Claims. (Cl. 260576) This invention relates to a new class of N,N,N',N'- tetrakis(-p substituted phenyl) p phenylenediamines and benzidines. It also presents a process for making said new compounds and to their use as intermediates in making aminium and diimonium salts.

More particularly, the invention is concerned with diamines of the following Formula I Formula I wherein X is -NO or -NH and n is one or two.

It will be noted that the amines of Formula I are derivatives of two similarly N,N-substituted diarnino compounds; i.e., p-phenylenediamines (where 11:1) and benzidines (where 11:2). If so desired, the phenyl groups may be further substituted with groups which are inert in use, as for example, by lower alkyl or alkoxy, halogen, hydroxyl and the like.

The nitro compounds of this invention; i.e., the substituted p-phenylenediamines and benzidines of Formula I are prepared from readily available starting materials by the reaction illustrated in the following reaction scheme (A).

r l Alkali OgN- hal HgNfl/ NH: g 2 L J. oppe Formula II Formula III I N02 N02 Formula IV Reaction of a p-nitrohalobenzene of Formula II with a p-phenylenediamine or benzidine of Formula III is carried out in a suitable solvent, preferably dimethylformamide, in the presence of an alkali, such as sodium or potassium carbonate, and in addition optionally and preferably, in the presence of copper powder.

Illustrative p-nitrohalobenzenes of Formula II include,

for example, p-nit-rochlorobenzene, p-nitrobromobenzene,

p-nitroiodobenzene, p-nitrofluorobenzene, nitrobenzene, 2-chloro-5-nitrotoluene, ethylbenzene, 2-nitro-5-bromot-oluene, anisole and the like.

Illustrative p-phenylenediamines of Formula III when n is one include, for example, p-phenylenediamine, ptoluylenediamine and the like; and the benzidines (compounds of (III)) when n is two include benzidine, 3,3- dichlorobenzidine, o-tolidine, o-dianisidine, m-tolidine and the like.

Compounds of Formula I wherein X is NH i.e., the amino compounds are readily prepared by reduction of nitro compounds of Formula IV. This is done con- 3,4-dichlor0- 2-chloro-5-nitro- 2-chloro-5-nitro 3,251,881 Patented May 17, 1966 veniently by catalytic hydrogenation in a suitable solvent, again preferably dimethylformamide. Standard catalysts for the hydrogenation of aromatic nitro compounds may be used. These include palladium on charcoal and Raney nickel. This is illustrated by the following reaction scheme (B).

QjEQI NH: NH: (V)

EXAMPLE 1 .N,N,N',N'-TETRAKIS p-NITRO- PHENYL) -p -PHENYLENEDIAMINE A mixture of 10.8 parts (0.1 mol) of p-phenylenediamine, 94.5 parts (06 mol) of p-nitrochlorobenzene, 31.7 parts (0.23 mol) of potassium carbonate and 2 parts of copper powder are stirred and refluxed for 48 hours in parts dimethyltormamide. The mixture is then filtered and the solid washed well with dimethylformamide, water, acetone and then dried. There is obtained about 37 parts (59%) of red-brown solid, M.P. 387390 C. An eight fold run gave a 76% yield of product melting at 390 C. After recrystallization from nitrobenzene, a sample had a melting point of 390392 C., and the following analysis:

Calcd for C H N O C, 60.8; H, 3.4; N, 14.2. Found: C, 60.7; H, 3.5; N, 13.9.

EXAMPLE 2.-N,N,N',N'-TETRAKIS (p-NITRO- PHENYL) BENZIDINE OrN 3 A mixture of 9.2 parts (0.05 mol) of benzidine, 47.3

parts (0.3 mol) of p-nitrochlorobenzene, 16.6 parts (0.12

mol) of anhydrous potassium carbonate, 1.0 part of copper powder and 75 parts dimethylformamide is stirred and refluxed for four days. The mixture is then filtered, washed well with dimethylformamide, water, and acetone, and dried. About 24.0 parts of an orange powder is obtained (71% yield). Melting point 370-374 C.

EXAMPLES 3 TO 11 Various materials are substituted for the p-nitrochlorobenzene and p-phenylenediamine or benzidine (of Formulae II and III respectively) in the procedure of Example 1 or 2. The starting materials and products are shown in the following Table I.

Q Table I STARTING MATERIALS Ex. (01) Formula (II) (of) Formula (III) No.

p-Ihenylenediamine. p-Toluylenediamine. Chloro-p-pheny]enediamine. Benzidine.

o-Tolidine.

o-Dianisidine.

m-Tolidine.

p-Nitrobromobenzene p-Nitroiodobenzene 3,4-dich1oronitrobenzene do... 2-chloro-5-nitrotoluene 2-cl1loro-5-nitroethylbenzene.. p-Nitroehlorobenzene 1o: o 3,3-Diehlorobenzidiue.

11 2-chlor0-5-nitronnis0le p'Phenylenediamme.

PRODUCTS OF FORMULA (IV) Example number N,N,N,N'-Tetrakis (p-nitrophenyl)-3 ,3'-dichlorobenzidine 1 1 N,N,N,N-Tetrakis o-methoxy-p-nitrophenyl) -pphenylenediamine EXAMPLE l2.N,N,N,N-TETRAKIS (p-AMINO PHENYL) -p-PHENYLENEDIAMINE 1 NH, NH;

A mixture of 29.6 parts (0.05 mol) of N,N,N',N-

EXAMPLE 13 .-N,N,N' ,N-TETRAKIS (p-AMINO- PI-IENYL) BENZIDINE NHz 15 A mixture of 24.0 parts (0.035 mol) of N,N,N,N-

tetrakis(p-nitrophenyl)benzidine (from Example 2), 1 part of 10% palladium-on-carbon catalyst and 100 parts of dimethylformamide is hydrogenated at 80 C. in a hydrogenation autoclave until the theoretical pressure drop is observed. The mixture is filtered and the filtrate is diluted with 300 parts of water. The solid which separates is recrystallized from a mixture of di'methylformamide and ethanol, giving about 11.2 parts (55% yield) of product, melting at 313 -316 C.

Calcd for C H N C, 78.8; H, 5.84; N, 15.3. Found: C, 77.9; H, 5.90; N, 16.7.

EXAMPLES 14 TO 21 In the procedure of Example 12 or 13, the products of Examples 3 to 11 are substituted for the p-phenylenediamine or benzidine compound of that example. The products are shown in the following Table II.

Table II Ex. Starting No. Cggmpfirom Product of Formula (V) 14. 4 N,N,g1,Nf'tetrakis(p'aminophenyl)-p-toluylene iamme. 15"--. 5 N,N,N,N-tetrakis(o-chloro-p-aminophenyl)- ehloro-phenylenedlamine. 16 6 NBNN dN -tetrakis(o-chloro-p-aminophenyl)- enzl me. 7 JYDJFSN-tetrakis(oqnethyl-p-aminophenyD- oo 1 me. l8 8 N,N,IaY-tetrakis(o-ethyl-p-aminophenyl)-olanisr me. 19 9 N,N,N,N-tetrakis(p-aminopl1enyl)-mtolidine.

20 10 N,II,N,N'-tetrakis(p-aminophcnyl)-3,3-

dlchlorobenzidine. 21 11 N,N,N,N-tetrakis(o-metlioxy-paminopheuynp-plienylenediamine.

As shown in the copending application Serial No. 281,059, filed May 16, 1963, by one of us; and our copending application Serial No. 281,056, also filed May 16, 1963; various aminium compounds such as tris(pdialkylaminophenyl)-aminiun1 salts previously have been proposed for use in various substrates to decrease transmission in the infrared region of the spectrum. Such salts do absorb strongly in the near infrared region of the spectrum. However, most elfective protection occurs in the vicinity of 960 millimicrons. Suitable compoundscapable of broad absorption at longer wave-lengths in the near infrared have been desired but in the past have not been available.

As shown in the above-noted applications, compounds having the desired properties are derived readily from compounds of Formula V, above, of the present invention. The compounds of that formula are converted to suitably substituted N,N,N',N-derivatives as shown in the' following reaction scheme (C).

NH: (V)

RZ l alkali a F UL IIIH:

R1 R R1 wherein R is allyl or an alkyl of one to twelve carbon atoms; R is selected from hydrogen and R; and n is again one or two; and RZ is an alkyl ester of an inorganic acid.

The amino compound of Formula V is reacted in a suitable solvent, such as aqueous acetone, with the reactant RZ which may be an alkyl halide such as methyl chloride, ethyl iodide, propyl bromide, butyl iodide, hexyl bromide, octyl bromide, dodecyl bromide and the like; or analkyl sulfate, such as methyl sulfate, ethyl sulfate and the like; or an alkyl arylsulfonate, such as methyl p-toluenesulfonate. An allyl halide, such as allyl bromide, also may be used. An alkali or alkaline salt such as sodium carbonate or potassium carbonate also normally is used. Reaction proportions and conditions are so selected that either one or two R groups per amino group are introduced. A typical illustration is shown in the following examples.

EXAMPLE 22.-N,N,N',N-TETRAKIS (p-DIETHYL- AMINOPHENYL) -p-PHENYLENEDIAMINE tained as a yellow-green solid, M.P. 214-215 C. Its analysis follows.

Calcd for C H N C, 79.3; H, 8.7; N, 12.1. Found:

C, 79.2; H, 8.7; N, 12.0.

EXAMPLE 23 .N,N,N,N-TETRAKIS (p-DIETHYL- AMINOPHENYL) BENZIDIN E A mixture of 11.0 parts (0.02 mol) of N,N,N,N-tetrakis(p-aminophenyl)benzidine (from Example 13), 37.4 parts (0.24 mol) of ethyl iodide, 22.1 parts (0.16 mol) of anhydrous potassium carbonate, and 160 parts of aqueous acetone is stirred and refluxed for 5 hours. The mixture is cooled and filtered, and the solid is washed well with water and then with acetone and dried. The product is recrystallized from hot dimethylformamide to give a solid, about 9.5 parts (62% yield), melting point 213- 214.5 C.

Calcd for C H N C, 80.83; H, 8.29; N, 10.88. Found: C, 78.21; H, 8.14; N, 11.49.

Compounds of Formula VI are then oxidized to the final desired protective aminium or diimonium salts by oxidation of the amino compounds. This is carried out in organic solvent solution by reacting the p-phenylenediamine or benzidine compound of Formula VI with a silver salt of a suitable acid. This general. method is shown in Neunhoeifer et al., Ben, 92, 245 (1959).

Dimethylformamide is a good solvent for use as the reaction medium. Others, such as acetone may be used. A wide variety of silver salts may be used. These include the perchlorate (CIO4 fluoborate (BF4 trichloracetate (CCl COO-), trifluoroacetate (CF COO), picrate (NO C H O-, hexafluoroarsenate (A F hexafluoro antimonate (SbF benzenesulfonate (C H SO ethanesulfonate (C H SO phosphate (PO sulfate (80 chloride (Cl) and the like.

Oxidation of one amino group of compounds of Formula VI produces aminium compounds of the following Formula VII:

R N/ X- R I -Q-eEQl (VII) and of two amino groups the diimoniurn compounds of the following Formula VIII;

(VIII) wherein, as above R is selected from allyl and the alkyls of one to twelve carbon atoms, R is selected from hydrogen and R, n is an integer selected from one or two and X'- is an anion.

This is shown in the following examples typical of the general procedure.

' 3,251,881 7 '3 EXAMPLE 24.-BIS(p DIETHYLAMINOPHENYL)- plastic or glass. This is done by any of several known [N,N BIS (p DIETHYLAMINOPHENYL) pprocedures, including, for example: solution casting or AMINOPHENYL] AMINIUM HEXAFLUOROAR- dipping; hot milling; burnishing; or by dyeing. Organic SENATE plastic material containing the salts can be molded into a formed articles such as sheets and plates. 2Hs)2 (CRKQTMSFF We claim:

1. A compound of the formula To a solution of 3.49 parts 0.005 mol) of N,N,N,N- x N N x tetrakis(p diethylaminophenyl) p phenylenediamine I L I (product of Example 22) in 25 parts of hot dimethylformamide is added 1.49 parts (0.005 mol) of silver hexafluoroarsenate in 25 parts of dimethylformamide. After stirring for /2 hour, the mixture is filtered and the filtrate I diluted with 350 parts of ether. On cooling in Dry-Ice- X X acetone mixture the product separates. There is obtained about 3.5 parts of green solid melting at l84-185 C.

EXAMPLE .-BIS (p DIETHYLAMINOPHENYL)- [N,N BIS(p DIETHYLAMINOPHENYL) 4'- AMINOBIPHENYL1AMINIUM HEXAFLUOROAR- wherein X is selected from the group consisting of NO SENATE 5 and NH and n is an integer selected from one and two.

I I(CrH5)z s)2 To a solution of 0.77 part 0.001 mol) of N,N,N',N'- A the frmula tetrakis(p-diethylaminophenyl)benzidine (product of Example 23) in 40 parts of acetone is added dropwise with 0rN-N-g NN0a stirring a solution of 0.30 part (0.001 mol) of silver hexafluoroarsenate in :5 parts of acetone. After stirring for about five minutes the mixture is filtered and the filtrate diluted with 200 parts of ethyl ether. On cooling in 40 Dry-Ice-acetone, a green solid separates, 0.71 part of l 1 product. N01 N02 EXAMPLE 26.1 I,N,N'N'-TETRAKIS(p DIETI-IYL- AMINOPHENYL) p BENZOQUINONE BIS- 3. A compound of the formula (IMONIUM HEXAFLUOROANTIMONATE) l(O:Ht)aN-1TIOI\| -N(c,n. 212sb-1 NO: NO:

N(C:H5)2 N(C:Hl)5 4. A compound of the formula To a stirred mixture of 1.39 parts (0.002 mol) of N,N,N,N' tetrak-is(p-diethylaminophenyl)-p-phenylenediamine (product of Example 22) in 20 parts of acetone is f r added 1.38 parts (0.004 mol) of silver hexafiuoroantiv monate. After stirring for one-half hour, the dark blue solution is filtered and the filtrate diluted with 100 parts of ether. The mixture is cooled and the solid which separates is collected, washed with ether and petroleum ether and dried. There is obtained 2.1 parts of product melting N51 with decomposition by 216 C.

Compounds of Formulae VII and VIII absorb broadly 5. A compound of the formula in the near infrared region of the spectrum at wavelengths longer than those obtained with compounds previously H \T available. Improved absorption is obtained in the region of longer wavelengths between about 1000 and about 1800 millimicrons. Many of the compounds also have desirable absorption at shorter Wavelengths in the near infrared region. These compounds also transmit a useful amount of visible light. I

In use, these salts may be incorporated in any suitable z plastic or applied on suitable transparent substrates of (References on following page) References Cited by the Examiner UNITED STATES PATENTS Nietzki, Deutsche Chemische Gesellschaft, Berichte,

1892, vol. 25, pp. 3005-3009.

Semon 2 0 57 X Piccar d, Helvetica Chimica Acta, 1924, vol. 7, pp. 789- Plantz et a1. 23232 5 799.

Merz 260-576 X Merz 260576 CHARLES B. PARKER, Primar Examiner.

DALE R. MAHANAND, ROBERT V. HINES,

Assistant Examiners. 

1. A COMPOUND OF THE FORMULA 